EPA Opens New Public Comment Period on WOTUS Water Definition Terms

The supplemental comment process extends the regulatory timeline for a rule that determines federal jurisdiction over millions of acres of wetlands and waterways, a question the Supreme Court...

The Environmental Protection Agency and the Army Corps of Engineers announced Friday that they will open a supplemental public comment period on three specific definitional terms within the Waters of the United States rule, commonly known as WOTUS, according to reporting by the Washington Examiner. The move further extends the agency's timeline for finalizing revisions to a rule that determines which bodies of water fall under federal regulatory authority under the Clean Water Act.

The two agencies said they are seeking public input on additional options for defining three terms: "relatively permanent," "continuous surface connection," and a third term that was not fully detailed in the published notice. The definitions govern which wetlands, streams, and other water bodies are subject to federal permitting requirements under the Clean Water Act.

The WOTUS rule has been the subject of sustained legal and regulatory contestation across multiple administrations. The Obama administration finalized a broad WOTUS rule in 2015. The Trump administration repealed and replaced it with the narrower Navigable Waters Protection Rule in 2020. The Biden administration reinstated an updated version of the broader Obama-era framework in 2023.

The current revision process was made necessary by the Supreme Court's May 2023 ruling in Sackett v. EPA, in which the Court held that the Clean Water Act's coverage of wetlands extends only to those with a continuous surface connection to a relatively permanent, standing, or flowing body of water. The decision, decided 5 to 4 with a majority opinion authored by Justice Samuel Alito, significantly curtailed the federal government's regulatory reach over wetlands and intermittent waterways. The case is a matter of public court record.

Following Sackett, the Biden EPA issued an amended rule in September 2023 removing language that the Court had found impermissible. The Trump administration, which returned to office in January 2025, has pursued further rollbacks. The current supplemental notice reflects the agency's effort to solicit comment on how to define the specific terms the Supreme Court identified as controlling.

The scope of WOTUS directly affects landowners, farmers, developers, municipalities, and environmental regulators. Property owners who wish to fill, dredge, or discharge into federally covered waters must obtain a Section 404 permit from the Army Corps of Engineers and, in some cases, a separate permit under Section 402 of the Clean Water Act administered by the EPA or authorized state agencies. The permit requirements carry civil and criminal penalties for violations, as documented in EPA enforcement records available through the agency's public enforcement database.

Agricultural interests have historically opposed broader WOTUS definitions, arguing that the rules subject ordinary farm drainage ditches and seasonal streams to federal permitting burdens. Environmental groups have argued that narrower definitions leave a significant share of the nation's wetland acreage without federal protection, relying on data from the EPA's own analyses, including a 2023 agency report estimating that the Sackett decision placed roughly half of the country's previously covered wetlands outside federal jurisdiction.

The supplemental comment process is a procedurally significant step. Under the Administrative Procedure Act, federal agencies must provide notice and an opportunity for public comment before finalizing rules. Supplemental notices are issued when an agency develops new regulatory options not covered in its original notice of proposed rulemaking, and they restart portions of the administrative clock, potentially delaying a final rule by months.

The Federal Register notice initiating the comment period had not been assigned a docket number in published reports available as of September 4, 2026. The length of the comment period was not specified in the Washington Examiner report. The full text of the supplemental notice, which would contain the complete list of the three terms under review and the specific options being considered, would be available in the relevant Federal Register docket on regulations.gov once formally published.

What remains unknown is the precise timeline the EPA and Army Corps of Engineers intend to follow for finalizing the revised WOTUS rule after the comment period closes. The agencies have not publicly announced a target date for a final rule. A regulatory agenda filing under the Unified Agenda of Regulatory and Deregulatory Actions, published by the Office of Information and Regulatory Affairs, would be the public record most likely to contain a projected finalization date.